Does anyone know of a decent calculator that uses Reverse Polish Notation that can be used as a desktop accessory?

To date I use the standard one that comes with Gnome, but it is arithmetic. Since I have used RPN since the dinosaurs roamed the earth, I would really like to find one. I've tried a few random ones I found from the net, but none were particularly good (sorry, the titles are long gone).

grpn is rather minimal. No statistical functions, for example, and you seem not to be able to set the display (number of significant digits, scientific notation, and so forth).

Still, it is a reasonable program for simple things. At some point, it makes sense to use a spreadsheet or actually (gasp!) write a program, but I am amazed at how often I still use the old HP calculator.